Composition for treating retinopathy or glaucoma comprising thrombin derived peptides

ABSTRACT

Disclosed is a composition for treating retinopathy comprising thrombin derived peptide as an effective component.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national stage filing under 35 U.S.C. §371of international application PCT/KR2007/004636, filed Sep. 21, 2007.

TECHNICAL FIELD

The present invention relates to a composition for treatingophthalmology disease comprising thrombin derived peptide.

BACKGROUND ART

Generally, representative ophthalmology diseases in reference toangiogenesis are Diabetic retinopathy and Retinopathy of prematuritywhich blood vessels are formed in the cornea, and Age-related maculardegeneration which blood vessels are formed in the choroid (Amal A. E.et al., Retina 11:244-249(1991); Constantin J. P. et al., Ophthalmology97:1329-1333(1990); Jin-Hong C. et al., Current opinion in Ophthalmology12:242-249(2001);Peter A. C., J of Cellular Physiology184:301-310(2000)) and Glaucoma.

Retinopathy of prematurity (ROP) is a major cause of loss of eyesight ininfants and occurs through two-step. Premature infants have anincomplete retinal blood vessel at the beginning of a birth, especiallythe premature infants who suffer from the progress of ROP have a risk ofinducing no growth of blood vessel in a retina (Flynn J. T. et al., ArchOphthalmol 95:217-223 (1977)). As a result, the retina is formed in ablood vessel-free state, resulting in formation of a low-oxygenperipheral retina (step 1 of ROP). In such step 1 of ROP, anon-perfusion level of retina determines a destructive stage including aretinal detachment and blindness caused by angiogenesis (step 2 of ROP)(Penn J. S. et al., Invest Ophthalmol Vis Sci 35:3429-435 (1994)). Ifblood vessel is normally developed in the retina of the prematureinfants, then a destructive stage may not be initiated due to asecondary angiogenesis in ROP. It has been known that use of highconcentration of oxygen is associated with such diseases, which meansthat an oxygen-regulated factor is present in the retina of prematureinfants.

It is anticipated that vascular endothelial growth factor (VEGF), whichis necessarily required to a normal angiogenesis and known as aoxygen-regulated factor, should take a important role in ROP, but it isknown from the various studies that VEGF act mainly in the first andsecondary stage of ROP (Pierce E.A. et al., Arch Ophthalmol114:1219-1228 (1996)). It was studied that VEGF expression is inhibitedin the first stage to affect the growth of blood vessel, using ROPanimal model (for example, high supplement oxygen).

Diabetic retinopathy is one of the most well known conditions amongmicrovessel-related complication mainly caused by hyperglycemia, andbecome a primary cause of acquired loss of sight in the adult (BrownleeM., Nature 414:813-820 (2001)). A serious loss of sight associated withdiabetic retinopathy is generated by means to retinal angiogenesis(Battegay E. J., J Mol Med 73:333-346 (1995)) and therefore vitreoushemorrhage and 4 tractional retinal detachment (Cai J., Boulton M., Eye16:242-260(2002)). Referring to a pathophysiological change in theretina of diabetic patients, the conditions such as loss of cellssurrounding capillary vessel, growth of basement membrane, loss ofautomatic control function in retinal blood vessel, abnormality ofcapillary circulation, microaneurysm, IRMA (intraretinal microvascularabnormalities) have appeared, finally resulting in formation of an areaof retinal non-perfusion (Lip P. L. et al., Invest Ophthalmol Vis Sci41:2115-2119 (2000); Hammes H. P. et al., Diabetes 51:3107-3112 (2002)).Such changes induce an increased vascular permeability, chronic retinalhypoxia and retinal ischemia through their continuous development toform macular edema or angiogenesis, resulting in progress intoproliferative diabetic retinopathy (Aiello L. P. et al., Diabetes Care21:143-156 (1998)). It seems that diabetic patients have an increasedlevel of a factor VEGF, and then the increased factor induces aretinopathy by destroying a retinal blood barrier.

Age-related macular degeneration is one of the major causes of blindnesswhich appears over 50 years old. Severe loss of sight results fromangiogenesis induced from capillary vessel of a choroidal neovascularmembrane (Ferris F. L. 3rd et al., Arch Ophthalmol 102:1640-1642(1984)). AMD is generally divided in 2 different types, for example wetAMD and dry AMD. It was known that development of wet AMD was followedby dry AMD. Dry AMD is referred to as the presence of maculardegeneration due to pigmentary degeneration of retina and loss ofretinal pigment epithelium (RPE). As the modified form of dry AMD, wetAMD shows conditions of subretinal neovascularization (subretinal scar),subretinal hemorrhage, detachment of RPE. In fact, subretinalneovascularization is meant to be a growing cicatricial tissue for atreatment of a space resulting from diseased RPE. Growth ofneovascularization allows plasma and cellulose to be extruded therefrom,causing a small retinal detachment (Mousa S. A. et al., J Cell Biochem74:135-43 (1999)). In addition, an injury caused by cicatrix ofsubretinal membrane may also result in weak eyesight.

Now, the method used to treat such ocular diseases includes lasertreatment, laser photocoagulation, cryocoagulation and Visudyne (EdwinE. B. et al., Ophthalmology 88:101-107 (1981)). All of such treatmentsare carried out by surgery, but treatment by therapeutic agents stillremains to be developed. Treatment by surgery has significant problemsof incapable to be applied to all patients, and it also hasdisadvantages of having low healing possibilities and very expensivecost. Accordingly, most of patients, who may not receive a surgery, maycome to blindness due to the lack of specific therapeutic agents. Alsoas human lives longer, these conditions continue to increase, but thetherapeutic agents still remain to be developed. Thus, many studies anddevelopments of angiogenesis inhibitors and therapeutic agents fortreating the ocular diseases are still carried out. And examples of suchagents include steroids, MMP inhibitor, antibodies against angiogenicgrowth factor and so on (Jeremy G. et al., Am J Pathology160:1097-1103(2002)).

DISCLOSURE OF INVENTION

Accordingly, the present invention is designed to solve the problems ofthe prior art, and therefore it is an object of the present invention toprovide a composition for treating ophthalmology disease.

In order to accomplish the above object, the present invention providesa composition for treating retinopathy or glaucoma comprising a thrombinderived peptide as an effective component.

The term “thrombin derived peptide” is used herein to mean a peptide,e.g., about 15 to 50 residues of amino acids including the peptide setforth in SEQ ID NO: 6 as a core sequence and the full sequence ofthrombin also can be included in the scope of the peptide.

In the preferred embodiment of the present invention, thrombin derivedpeptide is the peptide set forth in SEQ ID NO: 6 or is preferably someamino acids are added to N- terminal or C-terminal of the peptide setforth in SEQ ID NO: 6(i.e., the peptide sequence set forth in SEQ ID NO:3, SEQ ID NO: 5 or SEQ ID NO: 4) but is not particularly limited to thepeptides.

In the preferred embodiment of the present invention, the ophthalmologydisease includes disease, but are not particularly limited to, selectedfrom the group consisting of diabetic retinopathy, retinopathy ofprematurity, age-related macular degeneration, and glaucoma.

The peptides of the present invention reduce the abnormal formation ofthe vessels generated in retinopathy and stimulate the normal formationof vessels and decrease the leakage of the blood.

The formulation for treating eye diseases includes for example eye drop,eye ointment, oral preparation or percutaneously absorbable preparation.

The formulation used for administration of the compound into thesubTenon's space of the eye can be any form suitable for applicationinto the subTenon's space by injection through a cannula with smalldiameter suitable for injection into the subTenon's space. Examples forinjectable application forms are solutions, suspensions or colloidalsuspensions.

Compositions usable for injection into the subTenon's space contain aphysiologically tolerable carrier together with the relevant agent asdescribed herein, dissolved or dispersed therein as an activeingredient.

As used herein, the term“pharmaceutically acceptable” refers tocompositions, carriers, diluents and reagents which represent materialsthat are capable of administration into the subTenon's space of a mammalwithout the production of undesirable physiological effects. Thepreparation of an injectable pharmacological composition that containsactive ingredients dissolved or dispersed therein is well understood inthe art and need not be limited based on formulation. The preparationcan also be emulsified. The active ingredient can be mixed withexcipients which are pharmaceutically acceptable and compatible with theactive ingredient and in amounts suitable for use in the therapeuticmethods described herein.

Suitable excipients are, for example, water, saline, sorbitol, glycerolor the like and combinations thereof. In addition, if desired, thecomposition can contain minor amounts of auxiliary substances such aswetting or emulsifying agents, pH buffering agents, and the like whichenhance the effectiveness of the active ingredient. The composition canalso contain viscosity enhancing agents like hyaluronic acid.

Physiologically tolerable carriers are well known in the art. Exemplaryof liquid carriers are sterile aqueous solutions that contain nomaterials in addition to the active ingredients and water, or contain abuffer such as sodium phosphate at physiological pH value, physiologicalsaline or both, such as phosphate-buffered saline. Still further,aqueous carriers can contain more than one buffer salt, as well as saltssuch as sodium and potassium chlorides, sorbitol and other solutes.

Depending from the application form the active compound liberates in animmediate or a sustained release manner. A sustained release formulationis preferred because the injection frequency can be reduced.

One possibility to achieve sustained release kinetics is embedding orencapsulating the active compound into nanoparticles. Nanoparticles canbe administrated as powder, as powder mixture with added excipients oras suspensions. Colloidal suspensions of nanoparticles are preferredbecause they can easily be administrated through a cannula with smalldiameter.

Liposomes are a further drug delivery system which is easily injectable.Accordingly, in the method of invention the active compounds can also beadministered into the subTenon's space of the eye in the form of aliposome delivery system. Liposomes are well-known by a person skilledin the art.

Liposomes can be formed from a variety of phospholipids, such ascholesterol, stearylamine of phosphatidylcholines. Liposomes beingusable for the method of invention encompass all types of liposomesincluding, but not limited to, small unilamellar vesicles, largeunilamellar vesicles and multilamellar vesicles.

The term “the pharmaceutically effective amount”, “pharmaceuticaleffective amount” or “effective component” is used herein to mean theamount of drug or medicine which induces biological response ormedicinal response of tissue, system animal or human which researchersor doctors are desired. Proper response includes the prevention of onsetof the disease, the prevention of progress of the disease or theregression of the disease.

In the preferred embodiment, the administration of pharmaceuticallyeffective amount of the present invention treats retinopathy, morepreferably diabetic retinopathy, retinopathy of prematurity, andage-related macular degeneration.

The term “treating retinopathy” is used herein to include decreasing theabnormal angiogenesis, inducing the normal angiogenesis, decreasing thevascular leakage, and assisting stabilization of the blood vessels butis not limited to the description.

The pharmaceutical composition of the present invention may beadministered tropically or systemically. The systemic applicationincludes oral, transdermal, subcutaneous, intraperitoneal, nasal,hypoglossal, intramuscular, or rectal application. The tropicalapplication for administrating an eyeball includes intra-vitreous body,eye-circumference, trans-scleral, backward of an eye, sub-tenon ordevice in an eyeball. The preferred administration depends on thesymptom of angiogenesis in an eyeball and the properties of the disease

The pharmaceutical composition of the present invention includes morethan a pharmaceutically effective amount of peptide. The term“pharmaceutically effective amount of ” used herein to mean to besufficient amount to treat or prevent the eye diseases of the presentinvention. Generally, in composition for systemic application to treateye diseases, an effective amount of the composition including thepeptide and/or protein of the present invention may be preferablyadministered within a range of a bout 0.001 to about 100 mg/kg weight.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of preferredembodiments of the present invention will be more fully described in thefollowing detailed description, taken accompanying drawings. In thedrawings:

FIG. 1 is a diagram using a fluorescent FITC-dextran, showing comparisonof a retina (FIG. 1A) whose mouse does not exhibit a normal angiogenesisand a retina (FIG. 1B) whose mouse normally grows in a normal oxygenpartial pressure when the mouse retina is exposed to a high oxygenpressure in an animal model where mouse retinal angiogenesis is inducedby lowering the high oxygen pressure to a normal oxygen partial pressureafter the high-pressure oxygen treatment (75%).

FIG. 2 is a microscopic diagram showing that the new normal vesselsnormally are formed, and vascular leakage is decreased by thepolypeptide comprising a RGD sequence (SEQ ID NO 3—FIG. 2) when thepolypeptide is administered intraperitoneally in an animal model wheremouse retinal angiogenesis is induced by lowering the high oxygenpressure to a normal oxygen partial pressure after the high-pressureoxygen treatment (75%).

FIG. 3 is a comparison graph showing that a retinopathy score betweenthe experimental groups is digitalized by employing the method accessingthe retinopathy score disclosed in Higgins R. D. et al.,(Curr. Eye Res.18:20-27, 1999), compared to a retina (FIG. 1-A) exposed to a highoxygen pressure (75%) whose mouse does not exhibit a normal angiogenesisand a retina (FIG. 1-B) whose mouse normally grows in a normal oxygenpartial pressure and a retina(FIG. 2-A) of mouse which is administeredintraperitoneally with the polypeptide comprising a RGD sequence (SEQ IDNO: 3).

FIG. 4 is a diagram showing that normal angiogenesis is induced butabnormal angiogenesis is suppressed by the polypeptide comprising a RGDsequence (SEQ ID NOs: 1 and 2—FIGS. 4. A, B) when the polypeptidecomprising a RGD sequence is administered intraperitoneally in an animalmodel where mouse retinal angiogenesis is induced by lowering the highoxygen pressure to a normal oxygen partial pressure after thehigh-pressure oxygen treatment (75%).This figure reveal that thepolypeptides comprising a RGD sequence(SEQ ID NOs: 1 and 2) have thesame advantageous effect as the polypeptide comprising a RGD sequence(SEQ ID NO: 3; FIG. 2).

FIG. 5 is a diagram showing that normal angiogenesis is induced butabnormal angiogenesis is suppressed and the vascular leakage isdecreased by the polypeptide comprising a RGD sequence(SEQ ID NO: 4—FIG.5A) and the polypeptide comprising a RGD sequence(SEQ ID NO: 5—FIG. 5B)and the polypeptide comprising a RGD sequence(SEQ ID NO: 6—FIG. 5C) whenthe polypeptides are administered intraperitoneally in an animal modelwhere mouse retinal angiogenesis is induced by lowering the high oxygenpressure to a normal oxygen partial pressure after the high-pressureoxygen treatment (75%).

BEST MODES FOR CARRYING OUT THE INVENTION

Hereinafter, non-limiting preferred embodiments of the present inventionwill be described in detail with reference to the accompanying drawings.

EXAMPLE 1 Effects of RGD Sequence-Comprising Polypeptide (SEQ ID NO: 3)in Mouse Model for Inducing Retinal Angiogenesis Using Oxygen PartialPressure

The artificial ocular angiogenesis by oxygen partial pressure differenceexhibited the same pattern as in human retinopathy of prematurity anddiabetic retinopathy. This experiment was carried out using a principlethat abnormal angiogenesis is spontaneously induced when a mouse issubject to a high oxygen environment (75%) at an early stage of itsbirth, and then returned to a normal oxygen partial pressure (20%)(Higgins R D. et al., Curr. Eye Res. 18:20-27 (1999); Bhart N. et al.,Pediatric Res. 46:184-188 (1999); Gebarowska D. et al., Am. J. Pathol.160:307-313 (2002)). For this purpose, a mouse was kept for 5 days undera high oxygen environment with a constant 75% oxygen partial pressure 7days after the mouse was born in an apparatus that can adjust an oxygenpartial pressure, and then kept under a 20% oxygen pressure which is anormal oxygen partial pressure. At this time, the peptide (SEQ ID NO: 3)comprising a RGD sequence was administered intraperitoneally once everyfive days to observe whether or not the angiogenesis was induced in themouse eye. In order to observe the blood vessels, 50 mg of FITC-dextranhaving a molecular weight of 2×10⁶ was dissolved in 1 ml of saline, andthe resultant solution was injected through the left ventricle. Themouse eyeball was extracted immediately after the injection. Theextracted eyeball was washed with saline, fixed with 1% paraformaldehydefor 4 to 24 hours, and then a lens was removed from the eyeball. Then,the resultant mouse retina was evenly spread over a glass slide, and theglass slide was sealed with glycerine-gelatin, and then observed using afluorescence microscope.

It was observed that the blood vessels was uniformly distributed overthe entire retina of the mouse that grown in a normal oxygen partialpressure (B of FIG. 1), and the most angiogenesis was abnormal and theischemia was developed in the mouse that was treated with thehigh-pressure oxygen and then the saline (A of FIG. 1). However, it wasrevealed that the abnormal angiogenesis was not observed as well as thenormal blood vessels were observed in the mouse treated with 100ug/kg/day of the polypeptide(SEQ ID NO: 3) comprising a RGD sequence (Aof FIG. 2).

The degree on abnormal vessel, avascular lesion and vascular leakagecaused by the retinopathy was digitalized and the retinopathy score wascompared. (Higgins R. D. et al., Curr. Eye Res. 18:20-27, 1999) Theresult showed that mouse normally grows in a normal oxygen partialpressure was 0 and the abnormal vessel was not observed, but mouse ledto retinopathy by exposing to a high oxygen pressure was 12 and theabnormal vessel was significantly observed. While mouse which wasadministered with the polypeptide comprising a RGD sequence was 5 andabout 60% of the abnormal vessel caused by a high oxygen pressure wasnormalized (FIG. 3). This is a very interesting result in that thepolypeptide comprising a RGD sequence functions to help growth of normalblood vessels. Accordingly, the polypeptide (SEQ ID NO: 3) comprising aRGD sequence may be used as a therapeutic agent for treating oculardiseases avascular and abnormal angiogenesis such as diabeticretinopathy and age-related macular degeneration.

EXAMPLE 2 Effects of RGD Sequence-Comprising Polypeptide (SEQ ID NOs: 1,2 and 3) in Mouse Model for Inducing Retinal Angiogenesis Using OxygenPartial Pressure

In Example 2, an effect of the polypeptide (SEQ ID NOs: 1, 2 and 3)comprising a RGD sequence was confirmed in a mouse model for inducing anartificial retinal angiogenesis using oxygen partial pressure, asdescribed in Example 1. It was confirmed that the blood vessels areuniformly distributed over the entire retina in the mouse that grows ina normal oxygen partial pressure as described in Example 1 (B of FIG.1), and the most angiogenesis was abnormal and the ischemia wasdeveloped in the mouse that was treated with the high-pressure oxygenand then the saline (A of FIG. 1). It was revealed that the abnormalangiogenesis was decreased and the normal blood vessels were observed inthe mouse treated with all polypeptides (SEQ ID NOs: 1, 2 and 3)comprising a RGD sequence (A, B and C of FIG. 3). Especially, thepolypeptide (SEQ ID NO: 3) comprising a RGD sequence decreased theabnormal angiogenesis more than the polypeptide (SEQ ID NOs: 1 and 2)comprising a RGD sequence and the form of the vessel was like normalvessel. The result means that the polypeptide (SEQ ID NO: 3) comprisinga RGD sequence functions to help growth of normal blood vessels, asdescribed in Example 1. Accordingly, this result means that not only RGDsequence but also the longer peptide sequence comprising a RGD sequenceis necessary for the growth of normal blood vessels.

EXAMPLE 3 Effects of RGD Sequence-Comprising Polypeptide (SEQ ID NOs: 3,4, 5 and 6) in Mouse Model for Inducing Retinal Angiogenesis UsingOxygen Partial Pressure

In Example 3, an effect of the polypeptide (SEQ ID NO: 3,4,5 and 6)comprising a RGD sequence was confirmed in a mouse model for inducing anartificial retinal angiogenesis using oxygen partial pressure, asdescribed in Example 1. It was confirmed that the blood vessels areuniformly distributed over the entire retina in the mouse that grows ina normal oxygen partial pressure as described in Example 1 (B of FIG.1), and the most angiogenesis was abnormal and the ischemia wasdeveloped in the mouse that was treated with the high-pressure oxygenand then the saline (A of FIG. 1). It was revealed that the abnormalangiogenesis, avascular lesion and vascular leakage were decreased andthe normal blood vessels were observed in the retina treated with allpolypeptides (SEQ ID NOs: 3, 4, 5 and 6) comprising a RGD sequence (A,of FIGS. 2, A, B and C of FIG. 6). The result means that thepolypeptide(SEQ ID NOs: 4, 5, and 6) comprising a RGD sequence functionsto help growth of normal blood vessels, as described in Example 1. Andin addition to a TP508 (SEQ ID NO: 3), a Thrombin, the largerprotein(SEQ ID NO: 4) comprising the TP508 comprising the TP508, aprotein(SEQ ID NO: 5) comprising the TP508 but the size is smaller thanthe thrombin and a smaller peptide(SEQ ID NO: 6) than the TP508 had asimilar effect as the TP508. Accordingly, all peptides comprising a RGDsequence including TP508 may be used as a therapeutic agent for treatingocular diseases avascular and abnormal angiogenesis such as diabeticretinopathy and age-related macular degeneration, irrespective of thesize of the peptide.

The peptides and their sequences of the present invention are asfollows, the peptide of SEQ ID NO: 4 was purchased from Sigma company(U.S.A.) and the peptides of SEQ ID NOs: 1 and 2 were purchased fromBACHEM (Germany) and the peptides of SEQ ID NOs: 3, 5 and 6 wereprepared by chemical synthesis (Peptron., Daejeon, Korea).

SEQ ID NO: 1: Cyclo(-Arg-Gly-Asp-D-Phe-Val) SEQ ID NO: 2: H-Gly-Phe-Gly-Arg-Gly-Asp-Ser-Pro-Cys-Ala-OH SEQ ID NO: 3:Ala Gly Tyr Lys Pro Asp Glu Gly Lys Arg Gly AspGly Asp Ala Cys Glu Gly Asp Ser Gly Gly Pro Phe Val SEQ ID NO: 4:Met Ala His Val Arg Gly Leu Gln Leu Pro Gly CysLeu Ala Leu Ala Ala Leu Cys Ser Leu Val His SerGln His Val Phe Leu Ala Pro Gln Gln Ala Arg SerLeu Leu Gln Arg Val Arg Arg Ala Asn Thr Phe LeuGlu Glu Val Arg Lys Gly Asn Leu Glu Arg Glu CysVal Glu Glu Thr Cys Ser Tyr Glu Glu Ala Phe GluAla Leu Glu Ser Ser Thr Ala Thr Asp Val Phe TrpAla Lys Tyr Thr Ala Cys Glu Thr Ala Arg Thr ProArg Asp Lys Leu Ala Ala Cys Leu Glu Gly Asn CysAla Glu Gly Leu Gly Thr Asn Tyr Arg Gly His ValAsn Ile Thr Arg Ser Gly Ile Glu Cys Gln Leu TrpArg Ser Arg Tyr Pro His Lys Pro Glu Ile Asn SerThr Thr His Pro Gly Ala Asp Leu Gln Glu Asn PheCys Arg Asn Pro Asp Ser Ser Thr Thr Gly Pro TrpCys Tyr Thr Thr Asp Pro Thr Val Arg Arg Gln GluCys Ser Ile Pro Val Cys Gly Gln Asp Gln Val ThrVal Ala Met Thr Pro Ser Arg Glu Gly Ser Ser ValAsn Leu Ser Pro Pro Leu Glu Gln Cys Val Pro AspArg Gly Gln Gln Tyr Gln Gly Arg Leu Ala Val ThrThr His Gly Leu Pro Cys Leu Ala Trp Ala Ser AlaGln Ala Lys Ala Leu Ser Lys His Gln Asp Phe AsnSer Ala Val Gln Leu Val Gln Asn Phe Cys Arg AsnPro Asp Gly Asp Glu Glu Gly Val Trp Cys Tyr ValAla Gly Lys Pro Gly Asp Phe Gly Tyr Cys Asp LeuAsn Tyr Cys Glu Glu Ala Val Glu Glu Glu Thr GlyAsp Gly Leu Asp Glu Asp Ser Asp Arg Ala Ile GluGly Arg Thr Ala Thr Ser Glu Gly Gly Thr Phe PheAsn Pro Arg Thr Phe Gly Ser Gly Glu Ala Asp CysGly Leu Arg Pro Leu Phe Glu Lys Lys Ser Leu GluAsp Lys Thr Glu Arg Glu Leu Leu Glu Ser Tyr IleAsp Gly Arg Ile Val Glu Gly Ser Asp Ala Glu IleGly Met Ser Pro Trp Gln Val Met Ile Phe Gly MetSer Pro Trp Gln Val Met Cys Gly Ala Ser Leu IleSer Asp Arg Trp Val Leu Thr Ala Ala His Cys LeuLeu Tyr Pro Pro Trp Asp Lys Asn Phe Thr Glu AsnAsp Leu Leu Val Arg Ile Gly Lys His Ser Arg ThrArg Tyr Glu Arg Asn Ile Glu Ser Ile Ser Met LeuGlu Lys Ile Tyr Ile His Pro Arg Tyr Asn Trp ArgGlu Asn Leu Asp Arg Asp Ile Ala Leu Met Lys LeuLys Lys Pro Val Ala Phe Ser Asp Tyr Ile His ProVal Cys Leu Pro Asp Arg Glu Thr Ala Ala Ser LeuLeu Gln Ala Gly Tyr Lys Gly Arg Val Thr Ala AsnVal Gly Lys Gly Gln Pro Trp Thr Ala Asn Val GlyLys Gly Gln Pro Ser Val Leu Gln Val Val Asn LeuPro Ile Val Glu Arg Pro Val Cys Lys Asp Ser ThrArg Ile Arg Ile Thr Asp Asn Met Phe Cys Ala GlyTyr Lys Pro Asp Glu Gly Lys Arg Gly Asp Gly Asp Ala Cys Glu Gly Asp Ser Gly Gly Pro Phe Val Met Lys Ser Pro Phe Asn Asn Arg Trp Tyr Gln Met Gly Ile Val Ser Trp Gly Glu Gly Cys Asp Arg Asp Gly Lys Tyr Gly Phe Tyr Thr His Val Phe Arg Leu Lys Lys Trp Ile Gln Lys Val Ile Asp Gln Phe Gly Glu SEQ ID NO: 5:Arg Ile Arg Ile Thr Asp Asn Met Phe Cys Ala GlyTyr Lys Pro Asp Glu Gly Lys Arg Gly Asp Gly AspAla Cys Glu Gly Asp Ser Gly Gly Pro Phe Val Met Lys Ser Pro Phe Asn AsnSEQ ID NO: 6: Thrombin derivative-2 (Synthesized)Asp Glu Gly Lys Arg Gly Asp Gly Asp Ala Cys Glu Gly Asp Ser

1. A method for treating retinopathy, comprising administering to asubject a pharmaceutical composition containing a thrombin-derivedpeptide comprising the amino acid sequence set forth in SEQ ID NO:6 asan effective component, wherein the treatment for the retinopathy isindicative of decreasing abnormal angiogenesis, decreasing vascularleakage or assisting stabilization of blood vessels, and wherein theretinopathy is selected from the group consisting of diabeticretinopathy, retinopathy of prematurity, and wet age-related maculardegeneration.
 2. The method according to claim 1, wherein thethrombin-derived peptide comprises the amino acid sequence set forth inSEQ ID NO:3.
 3. The method according to claim 1, wherein thethrombin-derived peptide comprises the amino acid sequence set forth inSEQ ID NO:5.
 4. The method according to claim 1, wherein thethrombin-derived peptide comprises the amino acid sequence set forth inSEQ ID NO:4.